Expansible carrying case with band latch



June 17, 1969 H. G. DYKE 3,450,237

EXPANSIBLE CARRYING CASE WITH BAND LATCH Filed Aug. 24, 1967 sheet l of 2 V/////////// ll/ I June 17, 1969 H. G. DYKE EXPANSIBLE CARRYING CASE WITH BAND LATCH Sheej of 2 Filed Aug. 24, 1967 United States Patent O U.S. Cl. i90-44 19 Claims ABSTRACT F THE DISCLOSURE This carrying case is expansible at a peripheral joint between two of its portions through an entire cross-section. It has a peripheral ywall member all the way around the case that is movable relative to at least one of the two portions and which bridges the space between opposed peripheral edges of the two portions when the case is expanded. A closed loop latch band runs peripherally around the case and is movable bodily along its own peripheral length for at least a short travel. That band is operatively connected to latch the opposed edges of the peripheral joint together when it is in one position of peripheral travel and to release them so they can spread apart when it is in another position of peripheral travel. The band may carry spaced teeth while one of the portions of the case carries coacting spaced teeth.

This application is a continuation-in-part of my U.S. patent application No. 500,942, filed Oct. 22, 1965 and now abandoned.

The purpose of this invention is to provide a carrying case, especially a dispatch case for carrying papers, which can readily be enlarged to increase its capacity and can then be contracted again when desired.

At the time of buying a dispatch case it is not possible to know just how much bulk of papers it will need to accommodate. This may even change considerably in the course of a single business trip. The slim dispatch case looks smart and is trimmer to handle, but it often will not hold enough. An object of this invention is to provide a suitcase or dispatch case that will look trim and smart in normal retracted condition, but will be capable of being enlarged at any time to hold a larger bulk of papers or other contents while still being of presentable appearance in the enlarged condition.

A dispatch case or other carrying case made in accordance Iwith my invention will have a closed loop band running peripherally around its entire periphery where the expansion joint is. That band is movable bodily along its own peripheral length for at least a short travel. That band is operatively connected to latch the opposed edges of the peripheral joint together when it is in one position of peripheral travel and to release them so they can spread apart when it is in another position of peripheral travel.

It preferably performs this by operating latching members that are spaced about the periphery of the case. In the illustrative embodiments shown these latching members are two coacting sets of spaced teeth.

As seen in the drawings, the band running around the great periphery of the suitcase carries teeth that cooperate with generally corresponding teeth on a segment of the suitcase, preferably the outer segment, which moves out upon expansion. The band need be traveled lengthwise of its own periphery for only about a tooth length in order to selectively latch or unlatch the expansion segment.

Sheet 1 of the drawings shows my invention applied to a case with substantially rounded corners. The invention is particularly well adapted to use with a case whose rim ICC at least is quite stiff, such as a molded ration for enlarging the case is here accomplished by use of a continuous, flexible band that runs about the great periphery of the suitcase. In the form show there is provision for two independent enlargements of the suitcase, making the case generally symmetrical when both sides are closed in or both are expanded.

FIGURE 1 is a perspective of such a case.

FIGURE 2 is a fragmentary section on the line 2-2 of FIGURE 1.

FIGURE 3 is a section corresponding to FIGURE 2 but showing the band region expanded.

FIGURE 4 is a diagrammatic view showing the teeth on band and case.

FIGURE 5 is a section taken on the line 5 5 of FIG- URE 2 showing the teeth of FIGURE 4 interengaged, with the case contracted, that is to say, closed.

FIGURE 6 shows those teeth staggered so the case can expand.

FIGURE 7 is a perspective detail of the band.

FIGURE 7A is a fragmentary section of an alternate form of band made of elastomeric plastic.

FIGURES 8, 9 and 10 are diagrammatic views showing the ends of the bands joined together, and actuating linkage for moving the band lengthwise for a tooth length.

FIGURE 11 is a diagrammatic longitudinal vertical section of a sharp cornered case.

FIGURE 12 is a fragmentary section on the line 12-12 of FIGURE 13. l

FIGURE 13 is a fragmentary top view of a peripheral belt with bead and teeth, with part of the belts top layer cut away, showing the teeth engaged and the case held in its contracted configuration.

FIGURE 14 is a fragmentary section of the line 14-14 of FIGURE 15.

FIGURE 15 is a corresponding fragmentary top View with part of the belts top layer cut away, showing the teeth staggered and disengaged.

FIGURE 16 is a fragmentary section on the line 16-16 of FIGURE 17.

FIGURE 17 is a fragmentary top view with part of the belts top layer cut away, showing the relation of the teeth when the case is expanded.

FIGURE 18 is a fragmentary plan view of a corner portion of the band with rollers as seen at top and left of FIGURE 11.

FIGURE 19 is a corresponding side elevation.

FIGURE 20 is similar to FIGURE 12 but shows a foldable rather than stretchable collar gusset.

FIGURE 21 is a similar view butshows an accordionpleat collar gusset.

FIGURES 22-24 are a fragmentary showing of a thumb-knob arrangement for traveling the band by a tooth length, FIGURES 22, 23 and 24 being respectively top view, side view, and section on line 24-24 of FIG- URE 22, of same.

FIGURE 25 is a fragmentary section of part of a case showing a slightly stretchable anti-sag thong.

FIGURES 26 and 27 show another embodiment of my invention, FIGURE 26 being a section on the line 26-26 of FIGURE 27, and

FIGURE 27 being a fragmentary side elevation of part of a case with the top layer of the band removed.

When the two sets of teeth are free of each other the segments of the case can move apart to the extent of the width of a distensible peripheral collar that joins them and now serves as that portion of the case wall.

FIGURE 1 is a perspective view of a suitcase 100 incorporating this invention once at each side. The bands 108 may be of bright metal, which against a darker suitcase body can be rather handsomely distinctive. Or they may be of somewhat elastomeric plastic, which can elassuitcase. The sepatically withstand rough treatment, with color contrasts readily possible.

FIGURES 2 and 3 show, in fragmentary section, how the inner portion 101 and outer portion 102 of the rim part of the suitcase are divided at a parting plane, with a sponge-rubber gasket 103 glued to one of the rirn faces at that joint. They also show how the rim members are provided with channels 104, S with low wall members 106, 107 abruptly shouldering up on the parting plane side of each channel. This low wall member is, on one side-preferably the inner sidea continuous bead or wall 106, and on the other side intermittent teeth 107. The fastening and unfastening `band 108 runs peripherally about these channels and wall members. It is of thin flexible metal, such as brass or steel, and it has re-entrant portions curled down and inwardly at each edge. On the side whose channel has the continuous bead 106 alongside it, the band is formed with a bead 109 that is continuous except near the corners of the case. On the other side of the band, curled-under portions are also found which are similar to the bead except that they are intermittent lengths constituting teeth 110. A portion of the band is shown in perspective in FIGURE 7. It will be noticed also that the ends of the teeth and beads are rounded-in a little at 109a, l10n, to facilitate smooth sliding.

FIGURE 7A shows another band construction, if made of plastic. The tooth 109x would similarly be continuous except near the corners, while the teeth 110x would be intermittent, as in the form of FIGURE 7. Here teeth 110x are approximately quarter-round on their under-outer side, to facilitate bringing the case back to contracted configuration. The top of the band is preferably of ox-yoke shape across, to resist springing up out of engagement while not unduly resisting bending around the corners of the case.

FIGURE 4, at the upper right corner of Sheet 1, is a diagrammatic view showing the edge of the band 108 and its teeth 110 as they might be visualized in relation to the teeth 107 on the rim segment of the suitcase. As seen in FIGURE 4, the band teeth 110 and the rim teeth 107 are staggered. In this relation they are disengaged.

In FIGURE 5 there is shown diagrammatically the relation of the teeth 110 and 107 when they are engaged and the side segment of the suitcase is locked snugly in against the center segment. To make for easy understanding of the relationship, the bead 109 and teeth 110 of the band 108 have in this view been given small black index marks to show how they move together.

FIGURE 6 shows the band 108 having been advanced peripherally just over a tooth length. It will be noted that both on the band and on the case segment the distance between teeth is somewhat greater than the tooth length. The distance of travel of the band is a length between a tooth length and an intermittent blank length, so as to bring the band teeth 110 over to positions opposite the clear space between the case teeth 107. In this relation, which corresponds to the representation of FIGURE 4 at the top of the sheet, the band segment is free to move outwardly, with its teeth passing between the teeth on the case. The side segment of the case can therefore move out to an enlarged condition as shown in the fragmentary section of FIGURE 3. The band remains on the inner segment of the case (preferably) with its bead 109 remaining in the channel 104 and thus securing the band there.

The peripheral wall that encloses the space left between the inner segment and the outer segment of the case when it is in its enlarged condition may be a flexible collar gusset 111 running preferably around the inside of the case, folded upon itself so as to have a section of two reverse S curves 112 and 113, and solidly secured about both segments of the case by gluing and/or other securing means. When the casee is explained this gusset tiattens out at seen in FIGURE 3.

Some sort of grasping knob on the band is desirable, and it is even better to have a knob means which also limits the motion of the band -back and forth from the locked position of FIGURE 5 to the unlocked position of FIGURE 6, bringing the band to rest at one or the other of those positions selectively. It is better yet to have a means that gives a mechanical lever advantage t0 moving the band through this distance, and has a retracted rest position at each end of such limited excursions.

One mechanism to till the above requirements is shown in FIGURES 8, 9 and l0, which show also one means for tightening up the band after it is put in position on the case with its two ends fastened together to make it a continuous band. In FIGURE 8, which is a fragmentary plan view of these elements, there is shown a loop which has been passed through stub, curledback, ends 116, 117 of the band. These ends may be swedged down or spot welded. After the band is in place, with its bead in the channel about the inner segment of the case, this loop is pinched in as seen in FIGURE 8 to shorten it and snug the band permanently in place on the case. A squeezing tool not unlike pliers with two side spacing bars may be used for this squeezing operation to effectively shorten the band.

Also extending under the curled-back stub ends of the band are two heavy wire links 118, 119, bent Iback upon themselves in I shape as seen in FIGURE 9 (which is a side view of FIGURE 8) to effectively form slots 120, 121. A crank arm is pivoted to a suitable boss 123 on the case, The boss may be a molded part or a tted part. The crank arm 122 carries a heavy, short pin 124 projecting to the side and fitting into the slots 120, 121 of both the I -shaped links 118, 119. The various members have suitable rivet heads, studs, or the like to prevent their disengagement. The dimensional relations are that when the crank arm 122 is vertical, as in FIGURE 9, both lengths are long enough to allow this position, with the lpin being in the slots of both J links. The throw of the crank arm, twice the distance from-its end pivot to its stub pin, is suicient so that its pull of the band from one down position to the 180 opposite down position of the crank arm will move the band a little over one tooth length. In FIGURE 10 the band is shown moved to the unlocking position, ready to permit the carrying case to expand. Any desired detent means to hold the crank arm down to either side can be used; `as one example, the handle can tit fairly snugly in grooves 125 molded in the case to receive it. Thus it will stay down retracted and out of the Way as shown in fragmentary side elevation in FIGURE 10. Finger access depressions 126 can also be molded in for getting hold of the handle when it is desired to swing it over the other way.

The band 108 may desirably be of thin resilient metal, or of tough but flexible plastic. It rides in a peripheral shallow groove (between the far shoulders of channels 104 and 105) that has abrupt sides. When the band is put on it is tightened enough to it will stay in the channel but is not tightened enough to hind. When it is slid 1ength wise it has sliding contact with the groove floor and particularly with the portions at the rounded corners of the suitcase. Their radius s large enough so that sliding contact is feasible without requiring undue strain when the band is to be traveled along its length. If a plastic band is used the friction coeicient should be made low enough.

Since letters and other business papers have sharp, square corners, it is highly desirable that the interior of a dispatch case have sharp, square corners so the corners of the letters and other papers will not become dog-eared when they are carried around in the case. If, then, the bulk and probable weight of the case are not to be unduly increased, the exterior of the case is limited to rather small radius of curvature at the corners. The arrangement shown in Sheet 2 is particularly adapted to give expansibility in a case with small radius corners. It uses rollers at the corners, so the band can ride around them easily. This sheet also shows a telescopic form of expansible case with rows of staggered teeth.

With sharp-cornered cases, that is those having quite square inside corners and small-radius outside corners, it is more diflicult to have a taut-fitting band surround the case and slide peripherally along its own length at all easily. This form of the invention incorporates rollers to overcome that difficulty and provides rolling contact rather than sliding contact between the bands and the corner regions of the case.

FIGURE 11 is a fragmentary diagrammatic view of a dispatch case 130 with sharply square internal corners 131 and small external corner radius r1, and with even smaller channel radius r2. It has about it a metal band 132 divided into lengths for the separate sides, with its lengths being connected by sections of roller chain 133. The sections of roller chain are each long enough to round the small radius corner r2 of the dispatch case and extend in one direction an additional distance of about the length of one tooth which will be described below. The roller chain sections all have their extra length out from the rounded corner extending in the same rotary direction, which is counter-clockwise as illustrated in FIGURE 11. In use, the band as awhole will be moved clockwise for one tooth length, and then back again.

Before moving on to the other figures and describing the relationship of the teeth, it is pointed out that the lower right corner of FIGURE 11 illustrates an alternative embodiment. Here the flexible metal band 132 is continuous, and a pair of rollers 134 are mounted on the body of the dispatch case, immediately at the two sides of the sharp internal corner 131. Thus, while still permitting a minimum wall thickness of construction, the band has an anti-friction seat at its abruptly bent-around corner.

FIGURES 12 through 17 are somewhat diagrammatic fragmentary views, illustrating a portion of the case in the region where parting occurs to eliect enlargement.

In FIGURE 12 the exible metal band 132 is enlarged under one edge to form a bead 136 which is continuous except for the corner regions of the case. This bead fits down into, and rides in, a channel 138 formed near the edge of the body portion of the dispatch case. The band is held on by the abutting of the bead 136 against the two shoulder faces of channel 138, which rise up on both sides of the bead. Thus the band is movable along its own length, but not significantly movable in any other direction. The outer edge of the band has intermittent teeth 140 formed on its under edge. The outer segment of the case has an inwardly extending ledge 142 with intermittent teeth 144 rising up from it, spaced inwardly of the case from the outer shoulder 146 of the ledge. The teeth 140 on the band fit snugly between the teeth 144 on the ledge and the shoulder 146 of the ledge, locking the outer segment of the case snugly to the inner segment, and maintaining the case in slim, closed-in configuration.

When the band 132 is traveled lengthwise of itself for about one tooth length, it assumes the relation shown in FIGURE 15. Now the teeth 140 on the band are staggered in relation to the teeth 144 on the case. The outer segment of the case is free to move outwardly, and in FIGURE 17 it is shown as having done so. The case is now expanded and its capacity increased. Of course more than one of these arrangements can be built into the case. A desirable layout is to have one near each outer face of the case, whereby the case can ybe expanded selectively or symmetrically.

FIGURES 18 and 19 show some detail of the roller chain sections. They are respectively a plan view and side elevation. The metal band 132 terminates at a necked-in portion 132a, which is wrapped around a pin 148 of the roller chain and is secured by swedging, spot-welding, or as desired. Successive pins 148 bear rollers 140 until the last pin of the section is again secured to the band in like manner at another end. Links 152, 153 join successive pins in staggered pairs. The links can be secured to the pins in any desired manner, so long as at each pin we do not nonrotationally secure both an inner link 153 and an outer link 152 to the pin. A convenient arrangement is to have inner links 153 loose on the pins, for pivotal freedom, while outer links 152 are rigidly secured to both pins in each instance. Pivotal freedom is left for each roller to move up or down relatively independent of its adjacent neighbors. The anti-friction rotational freedom can be given between each pin and the roller sleeve it bears.

Between the body segment of the case and the enlargement segment that moves outwardly, a peripheral wall for the case interior is provided which accommodates itself to the selective enlargement. This Wall can be, as shown in -FIGURE 20', a collar 156 of pliable or bendable material such as fabric or sheet plastic. In the closed-in configuration, this peripheral collar 'is folded back upon itself in reversed S curves. Its fiat edge portions 157, 158 can be secured to the case by gluing or otherwise.

Alternatively, the collar 160 can be formed of flat, stretchable material such as rubber, polyurethane, or other elastomer. This is the form illustrated in FIG- URES 12-17. In FIGURE 17 it is shown stretched out and thereby thinned down between its edge portions that are secured in place. The secured edge portions 161, 162 stop considerably short of the parting line, in order to give a `greater stretchable width. This form has the advantage that it provides just such amount of enlargement of the case as the contents at any given time require, since they yforce the side of the case out against the resistance of the 'stretchable wall.

A form that permits such stretching in greater degree 'with lighter forces is shown in FIGURE 21. Here the peripheral collar 164 of elastomer is molded to incorporate intermittent accordion pleats 166. These will lie bet-Ween the opposed edge faces of the inner and outer segments of the case when the case is closed-in, and also serve as an anti-rattle gasket. They leave the interior sunface of the case qu-ite clean and fiat. A similar arrangement could be made using a light fiberboard thus folded instead of an elastomer. When the case is moved from the closed-in configuration of -lflG'URJ-l 21 to its enlarged condition, the accordion pleats 166 will unfold. If the contents of the case be even more voluminous, the elastomeric collar 164 can then stretch on out further.

At the upper right corner of Sheet 2 FIGURES 22-24 show an arrangement that yfacilitates moving the band for a tooth length back and Iforth along its own peripheral path, for enlarging the case and closing it back in.

Here suitable projecting lugs are provided which may be grasped and squeezed between the fingers to travel the band. A fixed lug 168 is provided on the top face of the case. This may be molded integrally with the case. It and its associated parts are seen in the three coordinate views of FIGURES 22-24 in which FIGURE 22 is a fragmentary top View, FIGURE 23 is a corresponding side elevation, and FIGURE 24 is a corresponding end elevation. On the band 132, two upstanding lugs 1170, 172 are provided, one on each side of the fixed lug. These are spaced apart by about a little over a tooth length plus the thickness of the fixed lug 168. When the fixed lug and one of the band lugs are squeezed together between the fingers, the band is moved to one predetermined position along its own path. When the fixed lugand the other band lug are squeezed together, the band is traveled by the distance specified, along its self path. The two end positions corresupond to the two positions of the band illustrated in FIGURES 13 and 15, one being the locked-together position and the other being the unlocked staggered position for enlargement. Detents such as the hinge-type detents 174, 176 shown in these figures may be provided ffor locking the band selectively in either position.

When the collar that provides the enlargement wall is made of stretchable material, there can be a tendency for the outer portions of the case, when it is enlarged, to sag downwardly. In FIGURE 25 there is illustrated somewhat diagrammatically a means for counteracting this. `Here an elongated bond 178 is provided; it has only a limited degree of stretchability, as for example on the order of a quarter of van inch lfor a bond l inches or 'a foot long. The bond may for example be a tape of composite elastomer and inelastic ilaments, the latter having a small amount of geometrical slack. 'Ihus when the case is opened up this bond can give a little to make up lfor the fact that it swings out on a rising arc centered at its top end. The limited degree of stretch and the small rise in this arc approximately cancel each other, leaving the enlarged case substantially without sag.

FIGURES 26 and 27 illustrate a modied lform of enlargeable dispatch case. FIGURE 26 is a ragmentary section showing part of the body segment 180 of the case, part of the movable side segment 182 of the case, and a cut through the actuating band 132". The movable side segment of the case has a wall ange 183 extending in some distance in telescoping relation to the, here, somewhat wider band 132". The outer surface of this wall flange bears intermittent staggered teeth 184, 185, 186; and at its parting line edge it bears a continuous upstanding low wall 187. These parts, and their relationship to their band 132", are shown diagrammatically in FIGURE 27.

As shown therein, the intermittent teeth 140 on the outer-under edge of the band engage the outermost teeth 184 of the movable segment 182 of the case and hold the segments together in closed-fin relation. As before, a bead 136 on the inner edge of the band is slidably locked into a shouldered channel 138 on the inner segment 180 of the case. If a rst stage of enlargement be desired, the band is advanced by a tooth length or so (downwardly as seen in FIGURE 27). This will move the band teeth 140 to staggered relation with the teeth 184 on the outermost row of the outer case segment. That segment can then move outwardly until the band teeth abut the next row 185 of case segment teeth. Successive rows of teeth on the case segment are in alternate staggered relation to each other. Then, if further' enlargement be desired, the band teeth 140r can be moved back to their first position, but now inboard of the lirst set 184 of teeth on the case segment. They will abut its third set of teeth 186 and hold the case at that degree of enlargement. A third stage of enlargement is obtained by moving the band teeth back (down) one unit to travel, whereupon they abut the generally continuous iinal low wall 187 of the ilange, which is like one continuous tooth. While three stages of expansion out from the closed-in position have been illustrated, this type of arrangement can of course be used to provide either more stages or fewer stages. With this torm of enlargement, as illustrated in FIGURES 26 and 27, no additional interior peripheral wall to the case is required, though a light stretchable liner may be provided for giving a smooth closed interior wall to the case at all times. The corner roller feature as shown in FIGURES 11, and 16 of this same sheet of drawings would desirably be combined with this modification, as would the actuating lugs oif FIGURE 22 or some other desired means for that same purpose.

It is to be understood that FIGURES 26 and 27 represent one edge wall segment in a case, and that similar arrangements would be provided for all four edge walls, with roller arrangements as in FIGURE l1 connecting them around the corners for unitary actuation. In this instance the wall ange 183 serves as part of the openable bond and as part of the wall bond.

In al1 the forms of this invention it is preferred that the wall bond be Continous about the entire great periphery and that the openable bond be at least intermittently continuous with @fastening elements or portions along all nfour edge ifaces of the case. The openable bond and the wall bond together constitute an expansible bond.

-I claim:

1. A carrying case expansible at a peripheral joint between two of its portions through an entire cross-section, having a peripheral wall member all the way around the case, said wall being movable relative to at least one of the two portions and bridging the space between opposed peripheral edges of the two portions when the case is expanded, and having a closed loop band running peripherally around the case movable bodily lfor at least a short travel along its own peripheral length, said band operatively connected to latch the opposed edges of the peripheral joint together when in one position of peripheral travel and to release them so they can spread apart when said band is in another position of peripheral travel.

2. Carrying case of claim 1 in which a plurality of latching members are disposed around the periphery of the case and are actuated by the band.

3. Carrying case of claim 2 in which the introduction into latching relationship of said latching members occurs by substantially simultaneous actuation of the members in the longitudinal direction of the joint line. Y

4. Carrying case of claim 2 in which the latching members are two sets of interlocking members with one set carried on the band.

5. Carrying case of claim 1 in which the carrying case has recessed edge portions which when together form a groove, and the band runs in that groove covering the joint line when the case is contracted.

6. Carrying case of claim 5 in 'which the case has a parting line within the groove and the band has continuous bead engagement with a channel in one side and intermittent teeth engagement with a channel on the other side.

7. Carrying case of claim 5 in which the band has its ends drawn together to reduce its length to less than the outside periphery o'f the case, so it is held in the groove.

8. Carrying case of claim 1 in which a pivoted arm is provided on the case, engaging links on the band for traveling the band along its own length for the latching and releasing travel.

9. Carrying case of claim 1 in 'which spaced lugs on the case and band permit grasping together to facilitate traveling the band.

10. Carrying case of claim 1 in which the corners olf the case are substantially rounded and the band is flexible and has sliding contact around the corners of the case.

11. Carrying case of claim 1 in which rollers are provided at the corner regions of the case to provide rolling contact of the bands around the corner regions of the case.

12. Carrying case of claim 11 in which the band is provided with lengths of roller chain at the corners of the case.

13. Carrying case of claim 11 in which the band is continuous and tlexible around the case and rollers are provided on the case at the corners to facilitate lengthwise travel of the band.

14. Carrying case of claim 1 in which the case is of hard molded construction and comprises two rim members at the two sides of the band with a parting line between them under the band, and beads on one of the rims and one edge of the band permanently engage while teeth on the other rim and the other edge of the band engage or disengage as the band is traveled lengthwise of itself.

15. Carrying case of claim 14 in which one of the interengaging band and rim members bears a plurality of spaced rows of intermittent staggered teeth for successive degrees of expansion.

16. Carrying case of claim 15 in which said peripheral wall member comprises an extensible wall bond having accordion pleats and tits, in part, between the directly opposed @faces of the expansibility parting joint.

17. Carrying case of claim 1 in which said peripheral Wall member comprises an extensible wall bond between the members that lie on the two sides of the openable peripheral joint.

18. A carrying case expansible at a peripheral joint between two of its portions through an entire cross-section, having a peripheral 'wall member all the `way around the case, said wall being movable relative to at least one of the two portions and bridging the space between opposed peripheral edges of the two portions when the case is expanded, and having an anti-sag thong secured near the top of the inner portion and near the bottom of the outer portion.

References Cited UNITED STATES PATENTS 892,125l 6/1908 Bourne 19o-45 2,536,169 1/1951 `Gray 190-44 X 2,691,401 10/1954 Kontotf et al. 190-52 X DONALD P. NORTON, Primary Examiner. 

